Thursday, May 29, 2014

OCCI - On chip Cooling Instruction

OCCI : On Chip Cooling Instructions

With increasing miniaturization of devices in recent times, power dissipated by devices in form of heat is a major challenge for chip manufacturers and end consumer device manufacturers. Heat is generated by all components like memory, processor, storage or any I/O controllers. For this post, I focus on processors only. Lets think about what processors do, basically they read some instructions and execute them. Today's microprocessor is a highly complex beast, with transistor size shrinking, we operate on lower voltages, combining many types of cores with varying capabilities, multiple levels of cache hierarchy etc. The size of chip is shrinking more and more.

Basis of this post is my hunch is that for a given processor, each instruction has a different heat profile. Also, for each instruction, there are certain group of transistors which get activated (which inherently could depend on the state)

So the question I ask is can we design some instructions which have negative heat dissipation OR absorb heat ?

At first glance, this sounds crazy right ? What do you think ?

Opinion

I think that it should be possible. Given that we have a large body of research in thermoelectric substances. Why can't nano thermocouples be fabricated in the processor itself and we can design instructions which activate them. The electricity generated by these thermocouples could further be harvested and used later. How exactly I don't know.